The project is a longitudinal study of males, under age 11, who show a marked degree of culturally feminine behavior. These boys prefer the dress, toys, games, and companionship of girls, role-play as females, display feminine gestures, and may state their wish to be girls. The boys are evaluated with extensive psychological testing and behavioral observation. Their parents are evaluated by the use of semi- structured tape-recorded interviews, psychological testing, and in dyadic interactional situations. Each family with a boy showing atypical sex-role development is matched with a family in which the contrast boy shows typical sex-role behavior. A project goal is to better understand the early life experiences associated with atypical and typical sex-role development in children.